Difficulties have been met for mounting the supporting arm when the sun-visor is covered over, in particular with plastic material. The covering is generally obtained by sealing the edges of two covering sheets applied on either side of the light screening body, along the periphery of the body.
According to a conventional production method, the supporting arm is constituted by a spindle fixed to the light screening body which is covered over with plastic material, during the screen covering operation. The spindle can have a section adapted to compensate for the thickness of the sealing line and to prevent any shifting of the covering when pivoting the sun-visor. It is however impossible, with this particular embodiment, to control the diameter of the supporting arm and the cooperation with the hook of the vehicle roof can cause, with time, tearing of the covering on the spindle.
It has been proposed, in order to overcome this difficulty, to remove the part of the covering which is around the spindle by providing circular notches near the edges of the indentation. But such cuts are always visible and unsightly, particularly when the covering is not made with a homogeneous material.
It has also been proposed to produce the supporting arm by means of two half-shells which are mounted on a rod made fast with the light screening body after the covering operation.
It is also known to use a method for mounting the supporting arm whereby the cuts made in the coating close to the edges of the supporting arm are invisible. This method consists in forcing back the parts of the covering around the cuts into the screening body of the sun-visor. But the supporting arm is more delicate to produce, since the cuts must be concealed on both sides of the indentation. The technique currently used consists in fixing the supporting arm on an added part which is fitted on one side of the indentation in a recess provided to this effect so as to press the covering into the sun-visor, as well as in the other side, in the opposite direction, to conceal the second cut. The problem with this technique is that it requires expensive tools and a long fitting time. Indeed, the sun-visor must be twisted in order to force-fit the added part into the cavity provided to this effect. What is more, this method does not permit the construction of thin screens.